X a alexander hato jm freemani



(No Model.)

` A. H. FREEMAN.

. ELECTRICAL MATTING.- No. 363,290.. Patented Mayl?, 1887.

a i a4 af# (1,4

UNITEE STATES PATENT OEEicEO ALEXANDER HAMILTON FREEMAN, OF NEW YORK, N.'Y Y.

ELECTRICAL NIATTING'.

SPECIFICATION forming part of Letters Patent No. 36.3,290, dated May 17, 1887.

Application tiled October 8, i586. Serial No. 215,653.

'New York, have invented a new and useful Improvement yin Electrical Matting; and I hereby declare the following to be a full and clear description ot' the same.

The object of this invention is vto form a cheap and thoroughly reliable electrical matting for use in connection with an alarm bell or gong, so that a person treadingon it will press the positive and negative systems of the matting together, so as to complete the electrical circuit to the alarm, and thus sound the alarm whenever any person steps on the said elect-rical matting.

The nature of the invention differs from electrical mattings heretofore constructed; and it consists of two sets of metallic straps or bars placed one above the other, with a strap or bar of an insulating material interposed between them, the three pieces secured together in a peculiar manner, as hereinafter described, so as to crimp or bend the said straps or bars of which the matting is composed in such amanner as to separate the metallic electrical conduits except when trod upon.

The invention will be readily understood b reference to the accompanying drawings, of

Whch-`- Figure l is a general plan of the improved matting. Fig. 2 is a sectional elevation showing the three bars of which the system is composed and the manner in which those bars are secured together,with erimps or longitudinal corrugations formed between the attaching-points of said bars.

The matting is formed of two sets of metallic straps or fiat bars, A and A, and an intervening strap or' bar, B, formed of any suitable non-conducting material. The bars A and A are riveted to the intermediate bar or strap, B, respectively, bythe rivets a and a', and the Vthree pieces are so placed. and conformed, each to the other, that each of the said pieces forms crimps or longitudinal corrugations between their respective riveting-points, so'as to form interstices or open spaces a2 and a, respectively, between the straps A B and A B. The rivets ct and a are placed so that their inner ends respectively terminate in the interstices (No model.)

or open spaces a2 and a3 when the mat is lying in its normal free condition; but when a weight-as of a person treading on it-is applied to its upper side the upper strap or bar,

A, is pressed down toward the lower strap or bar, A', so that the inner ends of theattaching-rivets a and a will form an electrical contact, respectively, with the opposite metallic bar, A or A', as the case may be, and thus complete thc circuit and sound the alarm. In forming these compound bars into a mat the bars or straps A project beyond their fellows at one end of the mat, and are then riveted to a connecting bar, A2, to one end of which is attached the positive conducting-wire P, and in like manner the opposite ends of thc pieces or straps A are attached to the negative conduit-wire N. The said Wires P and N connect the mat (respectively) with the battery and alarm or lgong (not shown) in the usual manner.

It is evidentthat an equivalent effect would be produced if the pieces A B A were fastened together so that only one of them would be crimped or longitudinally corrugated, in which case the insulating-piece B would lie parallel with and in complete contact with one of the metallic strips, thus `forming only one set of the apertures a2 or aa, (as the case may be,) and in this case the metallic strip to which the insulating-strip was permanently secured in contact throughout its entire length would be apertured, as at the dotted lines a4 in Fig. 1,' so as to completely insulate the rivets by which the crimped piece was attached to the insulator B, and allow only the other set of rivets to form the make-and-break conduit. Having described my invention, I claim- 1. An electrical alarm-mat formed of an upper and a lower set of metallic strips or bars with a non-conducting strip or bar interA posed between them and attached to the upper and lower metallic strips, respectively, by metallic rivets in such a form as to present crimps or longitudinal eorrugations in one or more of the said' strips between their said points of attachment, and thereby also form interstices or open spaces between the inner ends of said rivets and the adjacent me- ICQ tallic strip, so as to break the electrical con Y and close the circuit or conduit when the upspaces or nterstccs between the Suid riveted per section of the mab is pressed down upon points, combined and arranged substantially the lower section, substantially as described as described and set forth. and Set forth. ALEXANDER HMH'L'ION IEREIHIAN.

2. The electrical mat formed of the metallic bars A and A', the interposed non-conduct ing bar B, the rivets a and a', and the open XVi tnesses:

M. RANDOLPH, RUSSELL WroHT. 

